Final answer:
Overusing rescue medication can lead to respiratory depression and hypertension (option A,B) due to the potential side effects of drugs like epinephrine which lead to venoconstriction and increased blood pressure. Gastrointestinal bleeding is typically not a result of overusing these medications.
Step-by-step explanation:
From a pathophysiological perspective, the danger in overusing rescue medication, such as those for asthma or anaphylactic shock, typically includes various adverse effects. When it comes to rescue medications such as short-acting beta-agonists or epinephrine, one risk of overuse is respiratory depression, which can lead to reduced breathing rate and depth, and ultimately inadequate ventilation. Moreover, drugs like epinephrine, used for anaphylactic reactions, can also cause hypertension because they may lead to venoconstriction and increased blood pressure. Generally, gastrointestinal bleeding is not a direct consequence of overusing rescue inhalers or epinephrine. Instead, that's more commonly associated with the overuse of nonsteroidal anti-inflammatory drugs (NSAIDs) or other specific medications. Thus, the correct answer in the context of an adverse outcome of overuse of rescue medication would be respiratory depression (choice a).